RESUMEN
Immune-mediated processes represent a rapidly expanding categorical etiology for neurological disease manifestations spanning all subspecialties of neurology. Neural autoantibodies can be grossly divided into two main groups based on localization of the antigen: intracellular and cell membrane/synaptic antibodies. Antibodies reactive with neuronal membrane antigens have been identified in serum and cerebrospinal fluid of patients developing neurological disease either independent of or associated with cancer comorbidity, whereas antibodies directed against intracellular targets have a much higher rate of associated malignancy. Antibodies to neuronal membrane proteins such as the N-methyl-D-aspartate (NMDA) receptor are considered directly pathogenic based on disease models. Similar evidence exists for far fewer autoantibodies directed against intracellular targets. Attempts to produce an antibody-mediated animal model of human paraneoplastic disease have been unsuccessful to date. In this article, we review antineural antibodies and their clinical associations, briefly discuss recently characterized entities, and present proposed mechanisms of antibody pathogenicity.
Asunto(s)
Autoanticuerpos/sangre , Enfermedades Autoinmunes del Sistema Nervioso/inmunología , Proteínas del Tejido Nervioso/inmunología , Receptores de N-Metil-D-Aspartato/inmunología , Animales , Autoanticuerpos/inmunología , Encefalitis/inmunología , Humanos , Enfermedades del Sistema Nervioso/complicaciones , Enfermedades del Sistema Nervioso/inmunologíaRESUMEN
Neurofibromatosis type 1 (Nf1) mutation predisposes to benign peripheral nerve (glial) tumors called neurofibromas. The point(s) in development when Nf1 loss promotes neurofibroma formation are unknown. We show that inactivation of Nf1 in the glial lineage in vitro at embryonic day 12.5 + 1, but not earlier (neural crest) or later (mature Schwann cell), results in colony-forming cells capable of multilineage differentiation. In vivo, inactivation of Nf1 using a DhhCre driver beginning at E12.5 elicits plexiform neurofibromas, dermal neurofibromas, and pigmentation. Tumor Schwann cells uniquely show biallelic Nf1 inactivation. Peripheral nerve and tumors contain transiently proliferating Schwann cells that lose axonal contact, providing insight into early neurofibroma formation. We suggest that timing of Nf1 mutation is critical for neurofibroma formation.
Asunto(s)
Proteínas Hedgehog/metabolismo , Neurofibroma Plexiforme/patología , Neurofibromina 1/metabolismo , Neoplasias del Sistema Nervioso Periférico/patología , Pigmentación , Animales , Axones/metabolismo , Axones/patología , Proliferación Celular , Pérdida del Embrión , Embrión de Mamíferos/citología , Ganglios Espinales/citología , Integrasas/metabolismo , Ratones , Modelos Biológicos , Neurofibroma Plexiforme/ultraestructura , Neuroglía/citología , Neuroglía/metabolismo , Nervios Periféricos/metabolismo , Nervios Periféricos/patología , Receptor de Factor de Crecimiento Nervioso/metabolismo , Recombinación Genética , Células de Schwann/patología , Células de Schwann/ultraestructura , Nervio Ciático/metabolismo , Nervio Ciático/patología , Células Madre/citología , Células Madre/metabolismoRESUMEN
OBJECTIVE: Aquaporin-4 (AQP4) serum autoantibodies are detected by a variety of methods. The highest sensitivity is achieved with cell-based assays, but the enzyme-linked immunosorbent assay (ELISA) is still commonly utilized by clinicians worldwide. METHODS: We performed a retrospective review to identify all patients at the University of Utah who had AQP4 ELISA testing at ARUP Laboratories from 2010 to 2017. We then reviewed their diagnostic evaluation and final diagnosis based on the ELISA titer result. RESULTS: A total of 750 tests for the AQP4 ELISA were analyzed, and 47 unique patients with positive titers were identified. Less than half of these patients (49%) met the clinical criteria for neuromyelitis optica spectrum disorder (NMOSD). In cases of low positive titers (3.0-7.9 U/mL, n = 19), the most common final diagnosis was multiple sclerosis (52.6%). In the moderate positive cohort (8.0-79.9 U/mL, n = 14), only a little more than half the cohort (64.3%) had NMOSD. In cases with high positives (80-160 U/mL, n = 14), 100% of patients met clinical criteria for NMOSD. CONCLUSIONS: Our data illustrates diagnostic uncertainty associated with the AQP4 ELISA, an assay that is still commonly ordered by clinicians despite the availability of more sensitive and specific tests to detect AQP4 autoantibodies in patients suspected of having NMOSD. In particular, low positive titer AQP4 ELISA results are particularly nonspecific for the diagnosis of NMOSD. The importance of accessibility to both sensitive and specific AQP4 testing cannot be overemphasized in clinical practice.
RESUMEN
The study of peripheral nerve function in development and disease can be facilitated by the availability of cultured cells that faithfully mimic in vivo Schwann cell growth, maturation, and differentiation. We have developed a method to establish purified mouse Schwann cell culture from a single embryo at embryonic day 12.5 (E12.5) to define the abnormalities in Schwann cells caused by loss of the neurofibromatosis type 1 (Nf1) tumor suppressor protein, the RAS-GAP neurofibromin. Our method generates 2-3 x 10(6) cells/embryo highly purified (>99.5%) mouse Schwann cells in less than 2 weeks from a single E12.5 mouse embryo. Manipulation of cell medium allows purification of a Schwann-like cell population, termed Nf1-/-TXF, that resembles a tumorigenic cell in that it grows dissociated from axons and grows rapidly, yet retains expression of Schwann cell markers. We describe the preparation and characterization of both cell types.
Asunto(s)
Neurofibromina 1/fisiología , Células de Schwann/metabolismo , Animales , Técnicas de Cultivo de Célula/métodos , Separación Celular , Embrión de Mamíferos/citología , Ratones , Mutación , Neurofibromina 1/genética , Fenotipo , Células de Schwann/citologíaRESUMEN
It has been shown that African Americans (AAs) are more sensitive to experimental pain stimuli compared to non-Hispanic Whites (NHWs). A single bout of exercise results in naturally-occurring muscle pain and elevation in blood pressure (BP); however, it is currently unclear whether AAs and NHWs differ in muscle pain and BP responses during exercise. Therefore, we examined the differences in muscle pain and blood pressure (BP) during isometric handgrip exercise in African Americans (AAs) and non-Hispanic Whites (NHWs). Fourteen AAs and 14 NHWs completed isometric exercise consisting of squeezing a hand dynamometer at 25% of maximal strength for 3 min. During exercise, muscle pain ratings (MPRs) were assessed every 30s, whereas systolic and diastolic BP (SBP and DBP) were recorded every minute. During exercise, AAs generally reported greater MPR than NHWs (p<0.001), and MPR increased more rapidly during exercise in AAs than NHWs (p<0.05). In contrast, SBP and DBP continued to increase similarly during exercise in both AAs and NHWs (p>0.05). The results suggest that AAs generally experienced a greater intensity of muscle pain than NHWs during isometric handgrip exercise, but both groups exhibited similar elevations in BP during exercise.
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Presión Sanguínea/fisiología , Ejercicio Físico/fisiología , Mano/fisiología , Mialgia/etnología , Mialgia/fisiopatología , Negro o Afroamericano , Determinación de la Presión Sanguínea , Femenino , Fuerza de la Mano/fisiología , Humanos , Masculino , Dinamómetro de Fuerza Muscular , Dimensión del Dolor , Umbral del Dolor/fisiología , Población Blanca , Adulto JovenRESUMEN
Cancer biomarkers facilitate screening and early detection but are known for only a few cancer types. We demonstrated the principle of inducing tumors to secrete a serum biomarker using a systemically administered gene delivery vector that targets tumors for selective expression of an engineered cassette. We exploited tumor-selective replication of a conditionally replicative Herpes simplex virus (HSV) combined with a replication-dependent late viral promoter to achieve tumor-selective biomarker expression as an example gene delivery vector. Virus replication, cytotoxicity and biomarker production were low in quiescent normal human foreskin keratinocytes and high in cancer cells in vitro. Following intravenous injection of virus >90% of tumor-bearing mice exhibited higher levels of biomarker than non-tumor-bearing mice and upon necropsy, we detected virus exclusively in tumors. Our strategy of forcing tumors to secrete a serum biomarker could be useful for cancer screening in high-risk patients, and possibly for monitoring response to therapy. In addition, because oncolytic vectors for tumor specific gene delivery are cytotoxic, they may supplement our screening strategy as a "theragnostic" agent. The cancer screening approach presented in this work introduces a paradigm shift in the utility of gene delivery which we foresee being improved by alternative vectors targeting gene delivery and expression to tumors. Refining this approach will usher a new era for clinical cancer screening that may be implemented in the developed and undeveloped world.
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Biomarcadores de Tumor/metabolismo , Vectores Genéticos , Neoplasias/diagnóstico , Animales , Secuencia de Bases , Cartilla de ADN , Técnica del Anticuerpo Fluorescente , Humanos , Ratones , Neoplasias/patología , Simplexvirus/genéticaRESUMEN
BACKGROUND: Although disease remission can frequently be achieved for patients with neuroblastoma, relapse is common. The cancer stem cell theory suggests that rare tumorigenic cells, resistant to conventional therapy, are responsible for relapse. If true for neuroblastoma, improved cure rates may only be achieved via identification and therapeutic targeting of the neuroblastoma tumor initiating cell. Based on cues from normal stem cells, evidence for tumor populating progenitor cells has been found in a variety of cancers. METHODOLOGY/PRINCIPAL FINDINGS: Four of eight human neuroblastoma cell lines formed tumorspheres in neural stem cell media, and all contained some cells that expressed neurogenic stem cell markers including CD133, ABCG2, and nestin. Three lines tested could be induced into multi-lineage differentiation. LA-N-5 spheres were further studied and showed a verapamil-sensitive side population, relative resistance to doxorubicin, and CD133+ cells showed increased sphere formation and tumorigenicity. Oncolytic viruses, engineered to be clinically safe by genetic mutation, are emerging as next generation anticancer therapeutics. Because oncolytic viruses circumvent typical drug-resistance mechanisms, they may represent an effective therapy for chemotherapy-resistant tumor initiating cells. A Nestin-targeted oncolytic herpes simplex virus efficiently replicated within and killed neuroblastoma tumor initiating cells preventing their ability to form tumors in athymic nude mice. CONCLUSIONS/SIGNIFICANCE: These results suggest that human neuroblastoma contains tumor initiating cells that may be effectively targeted by an oncolytic virus.
Asunto(s)
Regulación Neoplásica de la Expresión Génica , Células Madre Neoplásicas/citología , Neuroblastoma/metabolismo , Virus Oncolíticos/metabolismo , Antígeno AC133 , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2 , Transportadoras de Casetes de Unión a ATP/biosíntesis , Animales , Antígenos CD/biosíntesis , Línea Celular Tumoral , Linaje de la Célula , Chlorocebus aethiops , Glicoproteínas/biosíntesis , Humanos , Proteínas de Filamentos Intermediarios/biosíntesis , Proteínas de Neoplasias/biosíntesis , Proteínas del Tejido Nervioso/biosíntesis , Nestina , Péptidos , Células Madre/metabolismo , Transcripción Genética , Células VeroRESUMEN
Defining growth factor requirements for progenitors facilitates their characterization and amplification. We characterize a peripheral nervous system embryonic dorsal root ganglion progenitor population using in vitro clonal sphere-formation assays. Cells differentiate into glial cells, smooth muscle/fibroblast (SM/Fb)-like cells, and neurons. Genetic and pharmacologic tools revealed that sphere formation requires signaling from the EGFR tyrosine kinase. Nf1 loss of function amplifies this progenitor pool, which becomes hypersensitive to growth factors and confers tumorigenesis. DhhCre;Nf1(fl/fl) mouse neurofibromas contain a progenitor population with similar growth requirements, potential, and marker expression. In humans, NF1 mutation predisposes to benign neurofibromas, incurable peripheral nerve tumors. Prospective identification of human EGFR(+);P75(+) neurofibroma cells enriched EGF-dependent sphere-forming cells. Neurofibroma spheres contain glial-like progenitors that differentiate into neurons and SM/Fb-like cells in vitro and form benign neurofibroma-like lesions in nude mice. We suggest that expansion of an EGFR-expressing early glial progenitor contributes to neurofibroma formation.
Asunto(s)
Transformación Celular Neoplásica/metabolismo , Receptores ErbB/metabolismo , Neurofibromatosis/genética , Neurofibromina 1/genética , Nervios Periféricos/metabolismo , Células Madre/metabolismo , Animales , Ciclo Celular/genética , Diferenciación Celular/genética , Linaje de la Célula/genética , Transformación Celular Neoplásica/genética , Células Cultivadas , Receptores ErbB/genética , Femenino , Ganglios Espinales/citología , Ganglios Espinales/metabolismo , Ganglios Espinales/fisiopatología , Predisposición Genética a la Enfermedad/genética , Humanos , Masculino , Ratones , Ratones Noqueados , Ratones Desnudos , Mutación/genética , Neurofibromatosis/metabolismo , Neurofibromatosis/fisiopatología , Neurofibromina 1/metabolismo , Nervios Periféricos/citología , Nervios Periféricos/fisiopatología , Células Receptoras Sensoriales/citología , Células Receptoras Sensoriales/metabolismo , Esferoides Celulares/citología , Esferoides Celulares/metabolismo , Células Madre/citologíaRESUMEN
Expression of the human epidermal growth factor receptor (EGFR) in murine Schwann cells results in loss of axon-Schwann cell interactions and collagen deposition, modeling peripheral nerve response to injury and tumorigenesis. Mast cells infiltrate nerves in all three situations. We show that mast cells are present in normal mouse peripheral nerve beginning at 4 weeks of age, and that the number of mast-cells in EGFR(+) nerves increases abruptly at 5-6 weeks of age as axons and Schwann cells dissociate. The increase in mast cell number is preceded and accompanied by elevated levels of mRNAs encoding the mast-cell chemoattractants Rantes, SCF and VEGF. Genetic ablation of mast cells and bone marrow reconstitution in W(41) x EGFR(+) mice indicate a role for mast cells in loss of axon-Schwann cell interactions and collagen deposition. Pharmacological stabilization of mast cells by disodium cromoglycate administration to EGFR(+) mice also diminished loss of axon-Schwann cell interaction. Together these three lines of evidence support the hypothesis that mast cells can contribute to alterations in peripheral nerves.
RESUMEN
Benign peripheral nerve tumors called neurofibromas are a major source of morbidity for patients with neurofibromatosis type 1. Some neurofibroma Schwann cells aberrantly express the epidermal growth factor receptor (EGFR). In a mouse model in which the CNPase promoter drives expression of human EGFR in Schwann cells, nerves develop hypertrophy, mast cell accumulation, collagen deposition, disruption of axon-glial interactions, characteristics of neurofibroma and are hypoalgesic. Administration of the EGFR antagonist cetuximab (IMC-C225) for 2 weeks beginning at birth in CNPase-hEGFR mice normalized all pathologies at 3 months of age as evaluated by hotplate testing or histology and by electron microscopy. Mast cell chemoattractants brain-derived neurotrophic factor, monocyte chemoattractant protein-1, and transforming growth factor-beta1, which may account for mast cell accumulation and fibrosis, were reduced by cetuximab. Later treatment was much less effective. A birth to 2-week pulse of cetuximab blocked hEGFR phosphorylation and Schwann cell prolifera-tion in perinatal mutant nerve, so CNPase-hEGFR Schwann cell numbers correlate with the cetuximab effect. A >250-fold enlarged population of EGFR(+)/p75(+) cells was detected in newborn Nf1(+/-) mouse nerves. These results suggest the existence of an EGFR(+) cell enriched in the perinatal period capable of driving complex changes characteristic of neurofibroma formation.